PROJECT SUMMARY/ABSTRACT The overall objective of the proposed research is to conduct community level research and to develop a multilevel, bio-psychosocial-ecological model of risk and protective factors for mental health (MH) and alcohol use disorders (AUDs) in Mexican American young adults (primarily second generation immigrants) in San Diego county. U.S.-born Mexican Americans have rates of alcohol use and psychiatric disorders that are higher than their Mexican-born ancestors and peers. This suggests trans-generational processes of adapting to life in the U.S. may play an important role in MH and health risk behaviors. The neighborhoods and communities in which these young adults settle also impact their health. Therefore, second generation Mexican Americans living near the border represent a population at high risk for health disparities. One theoretical approach to understanding the cause of these health disparities in immigrants is to envision the stress associated with acculturation as similar to other chronic psychosocial stressors that can over time lead to a dysregulation of the body's homeostatic function and thus impaired health. One measure of this dysregulation is allostatic load (AL) a term coined by McEwen and Stellar to operationalize the ?wear and tear? on the body caused by chronic stress over time. In this study, we will apply new measures of AL to an extension of a previously ascertained cross- sectional study of young adult Mexican American population (18-30 yrs) that has focused on individual bio-psychosocial factors that influence MH and AUDs. Those preliminary studies have demonstrated a distinct cluster of bio-psychosocial risk factors associated with MH, binge drinking and AUDs in this population. These associated factors include: early age of onset of drinking, reduced sleep quality, electrophysiological measures, co-morbidity of AUD with other psychiatric disorders, experience of trauma and post-traumatic stress syndrome, measures of acculturation stress, and distributions of alcohol metabolizing enzymes unique to this population. In the studies proposed here, we will: (1) Use geocoding procedures to obtain community/neighborhood data on our existing cohort and an expanded group of participants in order to increase power to identify contextual influences on pathways to AUD, including gene X environment interactions, and to evaluate gender differences; and (2) add a longitudinal study by following up with our existing cohort later in adulthood to determine if they have ?aged out? of early adult behavioral patterns or have developed more severe clinical outcomes. The longitudinal study also will enable assessment of effects of changes in acculturation and moving to a new community, or remaining in a high-risk neighborhood, on drinking and AUDs. Finally, we will, (3) use data from the expanded cross- sectional and longitudinal samples to develop a comprehensive bio-psychosocial-ecological model of MH and AUDs in Mexican Americans that includes individual genetic and physiological factors, as well as interpersonal and community influences. The proposed project brings together investigators with expertise in community studies, bio-psychosocial measures, biometrics and genetics to tackle this complex problem. Ultimately this study has the potential to provide critical information for understanding how select genetic and environmental factors might interact in the development of AUDs among Mexican American men and women living in in the U.S.-Mexico border region.